When it comes to computing there are several things that enthusiasts can never get enough of. One of those things is storage; we can always use more storage space. Western Digital has announced that it has added a new 4 TB capacity drive to its line of Black hard drives.

These drives are aimed specifically at enthusiasts and gamers and are 3.5-inch 7200 RPM units. Western Digital is shipping a new 4 TB capacity drives immediately and notes that the drives have a 64 MB cache. The drives also feature WD dual actuator technology and use the SATA 6 Gb/s interface.

The new 4 TB hard drives include a dual processor controller, IntelliSeek to calculate optimum seek speeds and lower the power consumption, and StableTrac. The drives also have NoTouch ramp load technology so that the recording head never touches the disk media for significantly less wear, extending the lifetime of the drive.

The 4 TB Western Digital Black WD40001FAEX hard drive will be offered through select distributors and resellers for $339. The drive includes a five-year warranty.

It's not really compression (though compression techniques using multi pass technologies have gotten lossless compression to better than 2:1 for generic data) or having the bits physically so close together that they are difficult to read (current read head technologies coupled with current partial response, maximum likelihood and other statistical reading techniques are plenty good enough to discern which bit is which even in higher areal densities than are common today).

It comes down to a permanence and density issue with technologies that are easily manufacturable. How many *STABLE* bits can you pack into a given area on a platter and still be able to make the platters cheap enough so the public will buy them?

Years ago bits were laid out in the surface plane of the platter. Then areal densities got high enough and those bits got small enough in area and they started affecting the stability of each other (nearby bits tended to flip to the same state rather than the written state). A long string of all 1s even though you wrote 10110001110000 is worthless.

Then researchers figured out how to do perpendicular bits with the magnetic domains written vertically into the platter (perpendicular to the surface of the platter). When manufactures figured out how to do this in a mass producible manner there was a significant jump in disc "size".

The current state of the art has hit against limits of what is easily manufacturable in areal densities again (how many bits you can pack into a square centimeter).

It's not that there are higher densities in the lab. There are. It's that no one has yet developed a manufacturing method that makes these higher density techniques profitable. Having a 10 TB 3.5" drive that costs $100/TB is not marketable.